Source

This directory contains a number of sample Emacs dynamic modules.
These modules can be loaded with the command 'M-x load-module'.
To compile one of these modules, simply enter the desired directory
and type 'make'. Then, from within Emacs, load the module by
specifying the path to the directory which contains the compiled
module.
Each of these samples describes different features and limitations
of the Emacs module loading technology. Please refer to the README
files in each directory for a brief discussion on what the sample
in that directory is demonstrating. For a complete discussion on
Emacs dynamic modules, please consult the Emacs Module Writers Guide,
which can be found in the ../info directory.
NOTE: As this technology matures, this directory will eventually contain
large parts of XEmacs itself, which will be loaded in as required.